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<html>
<head>
  <title>Test ScriptProcessorNode with passthrough</title>
  <script type="text/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
  <script type="text/javascript" src="webaudio.js"></script>
  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css" />
</head>
<body>
<pre id="test">
<script class="testbody" type="text/javascript">

// We do not use our generic graph test framework here because
// the testing logic here is sort of complicated, and would
// not be easy to map to OfflineAudioContext, as ScriptProcessorNodes
// can experience delays.

SimpleTest.waitForExplicitFinish();
addLoadEvent(function() {
  var context = new AudioContext();
  var buffer = null;

  var sourceSP = context.createScriptProcessor(2048);
  sourceSP.addEventListener("audioprocess", function(e) {
    // generate the audio
    for (var i = 0; i < 2048; ++i) {
      // Make sure our first sample won't be zero
      e.outputBuffer.getChannelData(0)[i] = Math.sin(440 * 2 * Math.PI * (i + 1) / context.sampleRate);
      e.outputBuffer.getChannelData(1)[i] = Math.sin(880 * 2 * Math.PI * (i + 1) / context.sampleRate);
    }
    // Remember our generated audio
    buffer = e.outputBuffer;

    sourceSP.removeEventListener("audioprocess", arguments.callee);
  }, false);

  function findFirstNonZeroSample(buffer) {
    for (var i = 0; i < buffer.length; ++i) {
      if (buffer.getChannelData(0)[i] != 0) {
        return i;
      }
    }
    return buffer.length;
  }

  var sp = context.createScriptProcessor(2048);
  sourceSP.connect(sp);

  var spWrapped = SpecialPowers.wrap(sp);
  ok("passThrough" in spWrapped, "ScriptProcessorNode should support the passThrough API");
  spWrapped.passThrough = true;

  sp.onaudioprocess = function() {
    ok(false, "The audioprocess event must never be dispatched on the passthrough ScriptProcessorNode");
  };

  var sp2 = context.createScriptProcessor(2048);
  sp.connect(sp2);
  sp2.connect(context.destination);

  var emptyBuffer = context.createBuffer(1, 2048, context.sampleRate);

  sp2.onaudioprocess = function(e) {
    // Because of the initial latency added by the second script processor node,
    // we will never see any generated audio frames in the first callback.
    compareChannels(e.inputBuffer.getChannelData(0), emptyBuffer.getChannelData(0));
    compareChannels(e.inputBuffer.getChannelData(1), emptyBuffer.getChannelData(0));

    sp2.onaudioprocess = function(e) {
      var firstNonZero = findFirstNonZeroSample(e.inputBuffer);
      ok(firstNonZero <= 2048, "First non-zero sample within range");

      compareChannels(e.inputBuffer.getChannelData(0), emptyBuffer.getChannelData(0), firstNonZero);
      compareChannels(e.inputBuffer.getChannelData(1), emptyBuffer.getChannelData(0), firstNonZero);
      compareChannels(e.inputBuffer.getChannelData(0), buffer.getChannelData(0), 2048 - firstNonZero, firstNonZero, 0);
      compareChannels(e.inputBuffer.getChannelData(1), buffer.getChannelData(1), 2048 - firstNonZero, firstNonZero, 0);

      if (firstNonZero == 0) {
        // If we did not experience any delays, the test is done!
        sp2.onaudioprocess = null;

        SimpleTest.finish();
      } else if (firstNonZero != 2048) {
        // In case we just saw a zero buffer this time, wait one more round
        sp2.onaudioprocess = function(e) {
          compareChannels(e.inputBuffer.getChannelData(0), buffer.getChannelData(0), firstNonZero, 0, 2048 - firstNonZero);
          compareChannels(e.inputBuffer.getChannelData(1), buffer.getChannelData(1), firstNonZero, 0, 2048 - firstNonZero);
          compareChannels(e.inputBuffer.getChannelData(0), emptyBuffer.getChannelData(0), undefined, firstNonZero);
          compareChannels(e.inputBuffer.getChannelData(1), emptyBuffer.getChannelData(0), undefined, firstNonZero);

          sp2.onaudioprocess = null;

          SimpleTest.finish();
        };
      }
    };
  };
});

</script>
</pre>
</body>
</html>
